Adjust Snap-to-Grid Distance in FontForge

Adjusting the snap-to-grid distance in FontForge allows font designers to control how aggressively points, handles, and paths align with coordinate lines and other anchor points. This guide covers how to modify FontForge's snapping sensitivity by changing the pixel threshold in the application preferences, as well as how to toggle the grid snapping behavior within the glyph editing window.

Modifying the Snapping Distance (SnapDistance)

In FontForge, the distance required to trigger a snap is measured in display pixels, rather than font design units. This means the setting determines how close your mouse cursor must be to a grid line or point before the element automatically jumps to it.

  1. Open FontForge.
  2. Navigate to File > Preferences (on macOS, go to FontForge > Preferences).
  3. In the Preferences window, select Editing from the left-hand sidebar.
  4. Locate the field labeled SnapDistance.
  5. Enter your desired value in pixels:
    • Lower values (e.g., 2–4): Require you to move the cursor closer to a grid coordinate or point to snap, offering finer manual control.
    • Higher values (e.g., 10–15): Make snapping trigger from farther away, making it easier to lock points quickly.
  6. Click OK to save your changes.

Enabling Snap to Grid

Once your snapping distance is configured, make sure the grid-snapping feature is enabled in your workspace:

  1. Open any glyph in the outline view (double-click a glyph in the font matrix).
  2. Open the View menu at the top.
  3. Ensure Snap to Grid is checked. If it is unchecked, click it to enable grid snapping.
  4. You can also toggle Snap to Points in the same menu if you want points to automatically snap to adjacent points within the threshold set by your SnapDistance.

Working with Coordinate Rounding

By default, FontForge works with integer coordinates. If your points are jumping automatically when released, the software is rounding them to the nearest integer grid.

To adjust whether coordinates automatically snap to integer values:

  1. Open Element > Font Info.
  2. Select the General tab.
  3. Check or uncheck Round (or adjust your EM size settings) depending on whether you require sub-pixel positioning or strict integer-aligned outlines.